But because of political correctness and the idea that there are to be no restrictions on an individual's actions whatsoever (under the guise of protection of civil liberties), they were not rounded up in the USA and their attack worked.
Note that in the original plan they hijacked planes outside of the USA, but the intelligence services of the Philippins prevented the attack. So...they went to the one country they could be assured would not profile them--ours. And the rest is history.
Very well put. When will we wake up?